refactor selector parsing

This commit is contained in:
ConnorSkees 2020-04-03 13:28:37 -04:00
parent 4565121b34
commit 2a01668ae0
4 changed files with 346 additions and 352 deletions

View File

@ -5,7 +5,9 @@ use std::string::ToString;
use super::{Selector, SelectorKind};
use crate::error::SassResult;
use crate::scope::Scope;
use crate::utils::{devour_whitespace, eat_ident, parse_interpolation, parse_quoted_string, is_ident_char};
use crate::utils::{
devour_whitespace, eat_ident, is_ident_char, parse_interpolation, parse_quoted_string,
};
use crate::Token;
#[derive(Clone, Debug, Eq, PartialEq)]
@ -24,9 +26,7 @@ impl Attribute {
) -> SassResult<SelectorKind> {
devour_whitespace(toks);
let attr = match toks.peek().ok_or("Expected identifier.")?.kind {
c if is_ident_char(c) => {
eat_ident(toks, scope, super_selector)?
}
c if is_ident_char(c) => eat_ident(toks, scope, super_selector)?,
'#' => {
toks.next();
if toks.next().ok_or("Expected expression.")?.kind == '{' {

View File

@ -6,8 +6,8 @@ use crate::error::SassResult;
use crate::lexer::Lexer;
use crate::scope::Scope;
use crate::utils::{
devour_whitespace, devour_whitespace_or_comment, eat_ident, eat_ident_no_interpolation,
parse_interpolation, IsWhitespace,
devour_whitespace, eat_comment, eat_ident_no_interpolation, parse_interpolation,
read_until_closing_paren, read_until_newline, IsWhitespace,
};
use crate::Token;
@ -16,7 +16,7 @@ use attribute::Attribute;
mod attribute;
#[derive(Clone, Debug, Eq, PartialEq)]
pub(crate) struct Selector(pub Vec<SelectorKind>);
pub(crate) struct Selector(Vec<SelectorPart>);
impl Selector {
pub const fn new() -> Selector {
@ -24,114 +24,127 @@ impl Selector {
}
}
impl Display for Selector {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
let mut iter = self.0.iter().peekable();
#[derive(Clone, Debug, Eq, PartialEq)]
struct SelectorPart {
pub inner: Vec<SelectorKind>,
pub is_invisible: bool,
pub has_newline: bool,
}
impl Display for SelectorPart {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
dbg!(&self);
let mut iter = self.inner.iter().peekable();
devour_whitespace(&mut iter);
while let Some(s) = iter.next() {
match s {
SelectorKind::Whitespace => continue,
SelectorKind::Attribute(_)
| SelectorKind::Pseudo(_)
| SelectorKind::PseudoElement(_)
| SelectorKind::PseudoParen(..)
| SelectorKind::Class
| SelectorKind::Id
| SelectorKind::Universal
| SelectorKind::InterpolatedSuper
| SelectorKind::Element(_) => {
write!(f, "{}", s)?;
if devour_whitespace(&mut iter) {
match iter.peek() {
Some(SelectorKind::Attribute(_))
| Some(SelectorKind::Pseudo(_))
| Some(SelectorKind::PseudoElement(_))
| Some(SelectorKind::PseudoParen(..))
| Some(SelectorKind::Class)
| Some(SelectorKind::Id)
| Some(SelectorKind::Universal)
| Some(SelectorKind::InterpolatedSuper)
| Some(SelectorKind::Element(_)) => {
write!(f, " ")?;
}
_ => {}
}
}
}
SelectorKind::Multiple => {
devour_whitespace(&mut iter);
while let Some(sel) = iter.peek() {
if sel != &&SelectorKind::Multiple {
write!(f, ",")?;
if sel == &&SelectorKind::Newline {
iter.next();
f.write_char('\n')?;
} else {
f.write_char(' ')?;
}
break;
}
iter.next();
write!(f, "{}", s)?;
if devour_whitespace(&mut iter) {
match iter.peek() {
Some(SelectorKind::Universal)
| Some(SelectorKind::Following)
| Some(SelectorKind::ImmediateChild)
| Some(SelectorKind::Preceding) => {
f.write_char(' ')?;
write!(f, "{}", iter.next().unwrap())?;
devour_whitespace(&mut iter);
}
while let Some(sel) = iter.peek() {
if sel != &&SelectorKind::Multiple
&& sel != &&SelectorKind::Newline
&& !sel.is_whitespace()
{
break;
if iter.peek().is_some() {
f.write_char(' ')?;
}
iter.next();
}
Some(..) => {
f.write_char(' ')?;
}
None => break,
}
_ => write!(f, "{}", s)?,
}
}
write!(f, "")
Ok(())
}
}
impl Display for Selector {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
for (idx, part) in self.0.iter().enumerate() {
write!(f, "{}", part)?;
if idx + 1 < self.0.len() {
f.write_char(',')?;
if part.has_newline {
f.write_char('\n')?;
} else {
f.write_char(' ')?;
}
}
}
Ok(())
}
}
#[derive(Clone, Debug, Eq, PartialEq)]
pub(crate) enum SelectorKind {
/// An element selector: `button`
/// Any string
///
/// `button`
Element(String),
/// An id selector: `#footer`
Id,
/// A single class selector: `.button-active`
Class,
/// A universal selector: `*`
Universal,
/// Multiple unrelated selectors: `button, .active`
Multiple,
/// Newline (significant if after `SelectorKind::Multiple`)
Newline,
/// Select all immediate children: `ul > li`
ImmediateChild,
/// Select all elements immediately following: `div + p`
Following,
/// Select elements preceeded by: `p ~ ul`
Preceding,
/// Select elements with attribute: `html[lang|=en]`
Attribute(Attribute),
/// Pseudo selector: `:hover`
Pseudo(String),
/// Pseudo element selector: `::before`
PseudoElement(String),
/// Pseudo selector with additional parens: `:any(h1, h2, h3, h4, h5, h6)`
PseudoParen(String, String),
/// Use the super selector: `&.red`
Super,
/// Super selector in an interpolated context: `a #{&}`
InterpolatedSuper,
/// Placeholder selector: `%alert`
Placeholder,
Whitespace,
}
impl IsWhitespace for SelectorKind {
fn is_whitespace(&self) -> bool {
self == &Self::Whitespace
}
/// An id selector
///
/// `#`
Id(String),
/// A class selector
///
/// `.`
Class(String),
/// A universal selector
///
/// `*`
Universal,
/// Select all immediate children
///
/// `>`
ImmediateChild,
/// Select all elements immediately following
///
/// `+`
Following,
/// Select elements preceeded by
///
/// `~`
Preceding,
/// Select elements with attribute
///
/// `[lang|=en]`
Attribute(Attribute),
Super,
/// Pseudo selector
///
/// `:hover`
Pseudo(String),
/// Pseudo element selector
///
/// `::before`
PseudoElement(String),
/// Pseudo selector with additional parens
///
/// `:any(h1, h2, h3, h4, h5, h6)`
PseudoParen(String, Selector),
/// Placeholder selector
///
/// `%`
Placeholder(String),
/// Denotes whitespace between two selectors
Whitespace,
}
impl IsWhitespace for &SelectorKind {
@ -144,215 +157,217 @@ impl Display for SelectorKind {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
match self {
SelectorKind::Element(s) => write!(f, "{}", s),
SelectorKind::Id => write!(f, "#"),
SelectorKind::Class => write!(f, "."),
SelectorKind::Id(s) => write!(f, "#{}", s),
SelectorKind::Class(s) => write!(f, ".{}", s),
SelectorKind::Universal => write!(f, "*"),
SelectorKind::Whitespace => write!(f, " "),
SelectorKind::Multiple => write!(f, ", "),
SelectorKind::Newline => writeln!(f),
SelectorKind::ImmediateChild => write!(f, " > "),
SelectorKind::Following => write!(f, " + "),
SelectorKind::Preceding => write!(f, " ~ "),
SelectorKind::ImmediateChild => write!(f, ">"),
SelectorKind::Following => write!(f, "+"),
SelectorKind::Preceding => write!(f, "~"),
SelectorKind::Attribute(attr) => write!(f, "{}", attr),
SelectorKind::Pseudo(s) => write!(f, ":{}", s),
SelectorKind::PseudoElement(s) => write!(f, "::{}", s),
SelectorKind::PseudoParen(s, val) => write!(f, ":{}({})", s, val),
SelectorKind::Super | SelectorKind::InterpolatedSuper => write!(f, ""),
SelectorKind::Placeholder => write!(f, "%"),
SelectorKind::Placeholder(s) => write!(f, "%{}", s),
SelectorKind::Super => todo!(),
SelectorKind::Whitespace => f.write_char(' '),
}
}
}
struct SelectorParser<'a> {
scope: &'a Scope,
super_selector: &'a Selector,
selectors: Vec<SelectorKind>,
is_interpolated: bool,
}
impl<'a> SelectorParser<'a> {
const fn new(scope: &'a Scope, super_selector: &'a Selector) -> SelectorParser<'a> {
SelectorParser {
scope,
super_selector,
selectors: Vec::new(),
is_interpolated: false,
}
}
fn all_selectors<I: Iterator<Item = Token>>(
mut self,
tokens: &'a mut Peekable<I>,
) -> SassResult<Selector> {
self.tokens_to_selectors(tokens)?;
// remove trailing whitespace
while let Some(x) = self.selectors.pop() {
if x != SelectorKind::Whitespace {
self.selectors.push(x);
break;
}
}
Ok(Selector(self.selectors))
}
fn consume_pseudo_selector<I: Iterator<Item = Token>>(
&mut self,
tokens: &'_ mut Peekable<I>,
) -> SassResult<()> {
if let Some(tok) = tokens.next() {
match tok.kind {
v @ 'a'..='z' | v @ 'A'..='Z' | v @ '-' | v @ '_' => {
let s = format!(
"{}{}",
v,
eat_ident(tokens, self.scope, self.super_selector)?
);
if let Some(Token { kind: '(', .. }) = tokens.peek() {
tokens.next();
devour_whitespace(tokens);
let mut toks = String::new();
while let Some(Token { kind, .. }) = tokens.peek() {
if kind == &')' {
tokens.next();
break;
}
let tok = tokens.next().unwrap();
toks.push_str(&tok.kind.to_string());
if devour_whitespace(tokens) {
toks.push(' ');
}
}
self.selectors
.push(SelectorKind::PseudoParen(s, toks.trim_end().to_owned()))
} else {
self.selectors.push(SelectorKind::Pseudo(s))
}
}
':' => {
let s = eat_ident(tokens, self.scope, self.super_selector)?;
self.selectors.push(SelectorKind::PseudoElement(s))
}
_ => return Err("Expected identifier.".into()),
}
}
Ok(())
}
fn tokens_to_selectors<I: Iterator<Item = Token>>(
&mut self,
tokens: &'_ mut Peekable<I>,
) -> SassResult<()> {
while tokens.peek().is_some() {
self.consume_selector(tokens)?;
}
Ok(())
}
fn consume_selector<I: Iterator<Item = Token>>(
&mut self,
tokens: &'_ mut Peekable<I>,
) -> SassResult<()> {
if devour_whitespace_or_comment(tokens)? {
if let Some(Token { kind: ',', .. }) = tokens.peek() {
tokens.next();
self.selectors.push(SelectorKind::Multiple);
return Ok(());
}
self.selectors.push(SelectorKind::Whitespace);
return Ok(());
}
if let Some(Token { kind, .. }) = tokens.peek() {
match kind {
'a'..='z' | 'A'..='Z' | '-' | '_' | '0'..='9' | '\\' => {
let s = eat_ident_no_interpolation(tokens)?;
self.selectors.push(SelectorKind::Element(s))
}
'.' => {
tokens.next();
self.selectors.push(SelectorKind::Class)
}
'#' => {
tokens.next();
if tokens.peek().is_some() && tokens.peek().unwrap().kind == '{' {
tokens.next();
self.is_interpolated = true;
self.tokens_to_selectors(
&mut Lexer::new(
&parse_interpolation(tokens, self.scope, self.super_selector)?
.to_string(),
)
.peekable(),
)?;
self.is_interpolated = false;
} else {
self.selectors.push(SelectorKind::Id)
}
}
':' => {
tokens.next();
self.consume_pseudo_selector(tokens)?
}
',' => {
tokens.next();
self.selectors.push(SelectorKind::Multiple);
if tokens.peek().unwrap().kind == '\n' {
self.selectors.push(SelectorKind::Newline);
devour_whitespace(tokens);
}
}
'>' => {
tokens.next();
self.selectors.push(SelectorKind::ImmediateChild)
}
'+' => {
tokens.next();
self.selectors.push(SelectorKind::Following)
}
'~' => {
tokens.next();
self.selectors.push(SelectorKind::Preceding)
}
'*' => {
tokens.next();
self.selectors.push(SelectorKind::Universal)
}
'%' => {
tokens.next();
self.selectors.push(SelectorKind::Placeholder)
}
'&' => self.selectors.push(if self.is_interpolated {
tokens.next();
SelectorKind::InterpolatedSuper
} else {
tokens.next();
SelectorKind::Super
}),
'[' => {
tokens.next();
self.selectors.push(Attribute::from_tokens(
tokens,
self.scope,
self.super_selector,
)?)
}
c if c.is_control() => {
return Err("expected selector.".into());
}
'`' => return Err("expected selector.".into()),
_ => todo!("unimplemented selector"),
};
}
Ok(())
}
fn is_selector_name_char(c: char) -> bool {
c.is_ascii_alphanumeric()
|| c == '_'
|| c == '\\'
|| (!c.is_ascii() && !c.is_control())
|| c == '-'
}
impl Selector {
pub fn from_tokens<'a, I: Iterator<Item = Token>>(
tokens: &'a mut Peekable<I>,
scope: &'a Scope,
super_selector: &'a Selector,
pub fn from_tokens<I: Iterator<Item = Token>>(
toks: &mut Peekable<I>,
scope: &Scope,
super_selector: &Selector,
) -> SassResult<Selector> {
SelectorParser::new(scope, super_selector).all_selectors(tokens)
let mut string = String::new();
while let Some(tok) = toks.next() {
match tok.kind {
'#' => {
if toks.peek().is_some() && toks.peek().unwrap().kind == '{' {
toks.next();
string.push_str(
&parse_interpolation(toks, scope, super_selector)?.to_string(),
);
} else {
string.push('#');
}
}
',' => {
while let Some(c) = string.pop() {
if c == ' ' || c == ',' {
continue;
} else {
string.push(c);
string.push(',');
break;
}
}
}
'/' => {
if toks.peek().is_none() {
return Err("Expected selector.".into());
} else if '*' == toks.peek().unwrap().kind {
toks.next();
eat_comment(toks, &Scope::new(), &Selector::new())?;
} else if '/' == toks.peek().unwrap().kind {
read_until_newline(toks);
devour_whitespace(toks);
} else {
return Err("Expected selector.".into());
}
string.push(' ');
}
c => string.push(c),
}
}
while let Some(c) = string.pop() {
if c == ' ' || c == ',' || c == '\t' {
continue;
} else {
string.push(c);
string.push(',');
break;
}
}
let mut inner = Vec::new();
let mut is_invisible = false;
let mut has_newline = false;
let mut parts = Vec::new();
// HACK: we re-lex here to get access to generic helper functions that
// operate on `Token`s. Ideally, we would in the future not have
// to do this, or at the very least retain the span information.
let mut iter = Lexer::new(&string).peekable();
while let Some(tok) = iter.peek() {
inner.push(match tok.kind {
_ if is_selector_name_char(tok.kind) => {
inner.push(SelectorKind::Element(eat_ident_no_interpolation(
&mut iter,
)?));
continue;
}
'&' => SelectorKind::Super,
'.' => {
iter.next();
inner.push(SelectorKind::Class(eat_ident_no_interpolation(&mut iter)?));
continue;
}
'#' => {
iter.next();
inner.push(SelectorKind::Id(eat_ident_no_interpolation(&mut iter)?));
continue;
}
'%' => {
iter.next();
is_invisible = true;
inner.push(SelectorKind::Placeholder(eat_ident_no_interpolation(
&mut iter,
)?));
continue;
}
'>' => SelectorKind::ImmediateChild,
'+' => SelectorKind::Following,
'~' => SelectorKind::Preceding,
'*' => SelectorKind::Universal,
',' => {
iter.next();
if iter.peek().is_some() && iter.peek().unwrap().kind == '\n' {
has_newline = true;
}
if !inner.is_empty() {
parts.push(SelectorPart {
inner: inner.clone(),
is_invisible,
has_newline,
});
inner.clear();
}
is_invisible = false;
has_newline = false;
devour_whitespace(&mut iter);
continue;
}
'[' => {
iter.next();
inner.push(Attribute::from_tokens(&mut iter, scope, super_selector)?);
continue;
}
':' => {
iter.next();
inner.push(Self::consume_pseudo_selector(
&mut iter,
scope,
super_selector,
)?);
continue;
}
c if c.is_whitespace() => {
if devour_whitespace(&mut iter) {
inner.push(SelectorKind::Whitespace);
}
continue;
}
_ => todo!(),
});
iter.next();
}
if !inner.is_empty() {
parts.push(SelectorPart {
inner,
is_invisible,
has_newline,
});
}
Ok(Selector(parts))
}
fn consume_pseudo_selector<I: Iterator<Item = Token>>(
toks: &mut Peekable<I>,
scope: &Scope,
super_selector: &Selector,
) -> SassResult<SelectorKind> {
let is_pseudo_element = if toks.peek().unwrap().kind == ':' {
toks.next();
true
} else {
false
};
if is_selector_name_char(toks.peek().unwrap().kind) {
let name = eat_ident_no_interpolation(toks)?;
Ok(
if toks.peek().is_some() && toks.peek().unwrap().kind == '(' {
toks.next();
let mut inner_toks = read_until_closing_paren(toks);
inner_toks.pop();
let inner = Selector::from_tokens(
&mut inner_toks.into_iter().peekable(),
scope,
super_selector,
)?;
SelectorKind::PseudoParen(name, inner)
} else if is_pseudo_element {
SelectorKind::PseudoElement(name)
} else {
SelectorKind::Pseudo(name)
},
)
} else {
todo!()
}
}
pub fn zip(&self, other: &Selector) -> Selector {
@ -361,67 +376,40 @@ impl Selector {
} else if other.0.is_empty() {
return self.clone();
}
let mut rules: Vec<SelectorKind> = Vec::with_capacity(self.0.len() + other.0.len());
let sel1_split: Vec<&[SelectorKind]> =
self.0.split(|sel| sel == &SelectorKind::Multiple).collect();
let sel2_split: Vec<&[SelectorKind]> = other
.0
.split(|sel| sel == &SelectorKind::Multiple)
.collect();
let len1 = sel1_split.len();
let len2 = sel2_split.len();
for (idx, sel1) in sel1_split.into_iter().enumerate() {
for (idx2, sel2) in sel2_split.iter().enumerate() {
let mut rules = Vec::with_capacity(self.0.len());
for sel1 in self.clone().0 {
for sel2 in other.clone().0 {
let mut this_selector: Vec<SelectorKind> = Vec::with_capacity(other.0.len());
let mut found_super = false;
for sel in *sel2 {
if sel == &SelectorKind::Super {
this_selector.extend(sel1.to_vec());
for sel in sel2.inner {
if sel == SelectorKind::Super {
this_selector.extend(sel1.clone().inner);
found_super = true;
} else if sel == &SelectorKind::InterpolatedSuper {
this_selector.extend(sel1.to_vec());
} else {
this_selector.push(sel.clone());
}
}
if !found_super {
rules.extend(sel1.to_vec());
rules.push(SelectorKind::Whitespace);
}
rules.extend(this_selector);
if !(idx + 1 == len1 && idx2 + 1 == len2) {
rules.push(SelectorKind::Multiple);
let mut x = std::mem::take(&mut this_selector);
let mut y = sel1.clone().inner;
y.push(SelectorKind::Whitespace);
y.append(&mut x);
this_selector = y;
}
rules.push(SelectorPart {
inner: this_selector,
is_invisible: sel1.is_invisible || sel2.is_invisible,
has_newline: sel1.has_newline || sel2.has_newline,
});
}
}
Selector(rules)
}
pub fn remove_placeholders(self) -> Selector {
let mut selectors = Vec::with_capacity(self.0.len());
let mut temp_sels = Vec::new();
let mut found_placeholder = false;
for sel in self.0 {
match sel {
SelectorKind::Placeholder => found_placeholder = true,
SelectorKind::Multiple => {
temp_sels.push(SelectorKind::Multiple);
if !found_placeholder {
selectors.extend(temp_sels.clone());
}
temp_sels.clear();
found_placeholder = false;
}
_ => temp_sels.push(sel),
}
}
if !found_placeholder {
selectors.extend(temp_sels);
}
Selector(selectors)
Selector(self.0.into_iter().filter(|s| !s.is_invisible).collect())
}
pub fn is_empty(&self) -> bool {

View File

@ -10,6 +10,12 @@ pub(crate) trait IsWhitespace {
fn is_whitespace(&self) -> bool;
}
impl IsWhitespace for char {
fn is_whitespace(&self) -> bool {
self.is_ascii_whitespace()
}
}
pub(crate) fn devour_whitespace<I: Iterator<Item = W>, W: IsWhitespace>(
s: &mut Peekable<I>,
) -> bool {

View File

@ -80,8 +80,7 @@ test!(
);
error!(
attribute_attr_quoted,
"[\"attr\"=val] {\n color: red;\n}\n",
"Error: Expected identifier."
"[\"attr\"=val] {\n color: red;\n}\n", "Error: Expected identifier."
);
test!(selector_attribute_in, "[attr~=val] {\n color: red;\n}\n");
test!(
@ -287,11 +286,11 @@ test!(
"#foo #bar,,\n,#baz #boom, {a: b}",
"#foo #bar,\n#baz #boom {\n a: b;\n}\n"
);
// test!(
// trailing_comma_children,
// "a,, {\n b {\n color: /**/red;\n }\n}\n",
// "a b {\n color: red;\n}\n"
// );
test!(
trailing_comma_children,
"a,, {\n b {\n color: /**/red;\n }\n}\n",
"a b {\n color: red;\n}\n"
);
test!(simple_placeholder, "%a {\n color: red;\n}\n", "");
test!(
placeholder_first,
@ -326,10 +325,11 @@ test!(
"ul li#foo {\n foo: bar;\n}\n"
);
test!(escaped_space, "a\\ b {\n color: foo;\n}\n");
// blocked on whitespace
// test!(multiple_consecutive_immediate_child,"> > foo {\n color: foo;\n}\n",);
test!(
multiple_consecutive_immediate_child,
"> > foo {\n color: foo;\n}\n"
);
error!(
modifier_on_any_attr,
"[attr i] {color: foo;}",
"Error: Expected \"]\"."
);
"[attr i] {color: foo;}", "Error: Expected \"]\"."
);